In the United States, the Clean Air Act established emission standards to regulate several pollutants that include nitrogen oxide (NOx), particulate matter (PM), carbon monoxide (CO), and hydrocarbons. One challenge for engine operators, under the Clean Air Act, is to limit the NOx emissions to comply with the ammonium g/bhp-hr standards. For operators of diesel engines, this standard proved to be problematic. One solution is known as the Selective Catalytic Reaction (SCR) technology.
SCR is an “after treatment” technology to reduce the NOx in the exhaust emissions of a diesel engine. The SCR relies upon an operating fluid called Diesel Exhaust Fluid or DEF. DEF is injected into the exhaust pipe in front of a SCR catalyst and downstream of the engine. The heat of the engine exhaust causes the DEF to decompose into ammonia. The NOx reacts with the ammonia in the catalyst and the NOx molecules are converted into N2 and H2O.
DEF is a solution that is about 32% of a high-priority area in deionized water the DEF is stored as a separate DEF tank, which is connected to the DEF injector. The average consumption of DEF is about 3% per gallon of diesel fuel so that the DEF tank is significantly smaller than the fuel tank.
Historically, operators would purchase DEF in small portable containers that would only hold a few gallons and use these portable containers to fill the DEF tanks associated with the diesel engine. Since about 3 gallons of DEF would be needed for about 100 gallons of fuel plastic containers from 35 to 15,000 gallons, over time, bulk containers began to appear and were located on-site of the operator so that the DEF tank was filled from a bulk dispenser.
However, storage of DEF began to exhibit problems due to the nature of DEF. For example, DEF freezes around 12° F. and will expand about 7%. As a result, the container expands and there is damage to the hose and pump. Additives should not be added to DEF to reduce the freezing point, as such additives can harm the SRC catalyst.
As DEF use increased, driven by the Clean Air Act, DEF dispensers were increasingly appearing at fuel islands so that DEF tanks could be refilled while filling diesel fuel tanks. However, given the limited space available at a fuel island, the tanks that would fit on the island had limited capacity. One solution was to stack containers or totes on top of one another so that the containers were arranged vertically to increase the storage capacity while maintaining the same footprint.
This arrangement was considered desirable given the vertical space between the ground and cover of a fuel island. The space could accommodate 18 wheel trucks. Unfortunately when the container on top needs to be filled, the fill opening has to be much higher than the operator can reach. As a result, a ladder is needed to fill the upper container. Having an operator stand on a ladder in a fuel island, while attempting to use a nozzle and hose to fill the upper container, is not desirable.
Another often overlooked disadvantage in the stacked configuration is that when a hose from the upper container is disconnected after filling or dispensing, the hose then becomes positioned lower than the upper container and fluid in the hose leaks out on to the ground or other undesirable location. Simply stacking two containers on top of one another is not the solution.
Another disadvantage with conventional storage containers is they are typically round to increase strength and prevent bulging. However, round containers typically do not properly fit on a fuel island and do not maximize the foot print for storage on a fuel island. Making a container with flat sides is advantageous for the fuel island, but the flat sides tend to bulge when a certain volume is reached so that the container extends over the fuel island. Attempts to strengthen the walls of a flat sided container lead to increased costs. Given the pressure of a full container, making one that is in excess of 10 feet in height results in a reinforced container that is not economical. It would be desirable to have a vertical shape system configured for a fuel island that could be filled completely from an operator at ground level.
Another difficulty created by the Clean Air Act is to have diesel engines that are used in remote areas to have DEF sources that are portable. For example, farm equipment, construction equipment, diesel engines, and the like. Many of these diesel engines operate in locations that are remote from fuel sources and therefore have high capacity fuel tanks. It would be advantageous to have a vertically stackable DEF source that can increase storage capability without increasing the footprint of the storage unit.
Additionally, portable DEF supplies also need to be refilled and it would be advantageous to be able to use the same hose, pump, and nozzle to fill the portable DEF source from a bulk container that is used to fill the DEF tank of a diesel engine from a DEF portable supply. It would also be advantageous to be able to refill the bulk container from a mobile DEF supply using the same pump configuration.
Therefore, it is an object of the present invention to provide for a vertical storage container that can be filled by an operator standing on the ground.
It is also an object of this invention to provide vertically stacked totes for storage of DEF.
It is also an object of the present invention to provide for a dispensing/fill assembly that can be used to fill the DEF source from a mobile storage container without duplicating the pump and hoses.